Add hint for glossaries beginner guide

As per reddit user's feedback

chapters/mainmatter/base-features.tex

@@ -945,11 +945,20 @@ \section{Censoring}
 \end{figure}
 
 \section{Glossaries}
+\label{ch:glossaries}
 
 \ctanpackage{glossaries-extra} is an absolute unit of a package.
 For this document, it is used with its back\-/end \ctanpackage{bib2gls}.
 This Java tool comes with installations of TeXLive and MiKTeX.
 You should already have it.
+This \lcnamecref{ch:glossaries} is only a brief, opinionated overview.
+For a more appropriate introduction, there is a suitable
+\href{http://tug.ctan.org/macros/latex/contrib/glossaries/glossariesbegin.pdf}{Beginner's Guide},
+written by the package author.
+Before you jump further into the relevant, proper documentations (these are three: the
+\ctanpackage{glossaries} base package, the comprehensive extension
+\ctanpackage{glossaries-extra} and the helper tool \ctanpackage{bib2gls}), you might
+want to give the beginner's guide a shot.
 
 In a format similar to normal bibliographies, all glossary entries are now managed
 using \texttt{*.bib} files.